Effects of chronic exposure to supranutritional sodium selenite (Se) were investigated in colonic fibroblasts. Initially, Se did not produce any gross changes in exposed cells; however, basal levels of autophagy were transiently increased and p38 activity was stimulated. From the 3rd week onwards, Se decreased cell proliferation, with corrensponding changes in cell cycle distribution. Also, in exposed cells oxidative stress and DNA damage slowly but gradually increased along with decreasing mitochondrial function and upon continued elevated activity of p38 kinase. Towards the end of the experiment, premature senescence features became more prominent in treated cells. Pharmacological inhibition as well as gene knockdown of these processes confirmed the involvement of p38 in balancing autophagy and premature senescence in cells exposed to Se and suggests that this element may in a given time frame compromise selected cell populations in digestive system.

• MeSH
• aktivace enzymů MeSH
• autofagie účinky léků   MeSH
• buněčné linie MeSH
• buněčný cyklus účinky léků   MeSH
• časové faktory MeSH
• fenotyp MeSH
• fibroblasty účinky léků   enzymologie   patologie   MeSH
• kolon účinky léků   enzymologie   patologie   MeSH
• lidé MeSH
• metylace DNA účinky léků   MeSH
• mitochondrie účinky léků   enzymologie   patologie   MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• poškození DNA MeSH
• proliferace buněk účinky léků   MeSH
• replikace DNA účinky léků   MeSH
• seleničitan sodný toxicita   MeSH
• signální transdukce účinky léků   MeSH
• stárnutí buněk účinky léků   MeSH
• transfekce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Many cancers arise at sites of infection and inflammation. Cellular senescence, a permanent state of cell cycle arrest that provides a barrier against tumorigenesis, is accompanied by elevated proinflammatory cytokines such as IL1, IL6, IL8 and TNFα. Here we demonstrate that media conditioned by cells undergoing any of the three main forms of senescence, i.e. replicative, oncogene- and drug-induced, contain high levels of IL1, IL6, and TGFb capable of inducing reactive oxygen species (ROS)-mediated DNA damage response (DDR). Persistent cytokine signaling and activated DDR evoke senescence in normal bystander cells, accompanied by activation of the JAK/STAT, TGFβ/SMAD and IL1/NFκB signaling pathways. Whereas inhibition of IL6/STAT signaling had no effect on DDR induction in bystander cells, inhibition of either TGFβ/SMAD or IL1/NFκB pathway resulted in decreased ROS production and reduced DDR in bystander cells. Simultaneous inhibition of both TGFβ/SMAD and IL1/NFκB pathways completely suppressed DDR indicating that IL1 and TGFβ cooperate to induce and/or maintain bystander senescence. Furthermore, the observed IL1- and TGFβ-induced expression of NAPDH oxidase Nox4 indicates a mechanistic link between the senescence-associated secretory phenotype (SASP) and DNA damage signaling as a feature shared by development of all major forms of paracrine bystander senescence.

• MeSH
• buněčné linie MeSH
• bystander efekt účinky léků   MeSH
• etoposid farmakologie   MeSH
• geny ras * MeSH
• interleukin-1 metabolismus   MeSH
• interleukin-6 metabolismus   MeSH
• Janus kinasy metabolismus   MeSH
• kultivační média speciální metabolismus   MeSH
• lidé MeSH
• NADPH-oxidasy metabolismus   MeSH
• NF-kappa B metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• parakrinní signalizace účinky léků   MeSH
• poškození DNA * MeSH
• proliferace buněk * MeSH
• proteiny Smad metabolismus   MeSH
• RNA interference MeSH
• signální transdukce účinky léků   MeSH
• stárnutí buněk účinky léků   MeSH
• transfekce MeSH
• transformující růstový faktor beta metabolismus   MeSH
• transkripční faktory STAT metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Ovarian surface epithelium (OSE) forms a single layer of mostly cuboidal cells on surface of mammalian ovaries that is inherently exposed to cell stress evoked by tissue damage every ovulation and declines morphologically after menopause. Endoplasmic reticulum (ER) is a principal cell organelle involved in proteosynthesis, but also integrating various stress signals. ER stress evokes a conserved signaling pathway, the unfolded protein response (UPR), leading to cell death or adaptation to stress conditions. In this work, we document that mouse OSE suffers from ER stress during replicative senescence in vitro, develops abnormalities in ER and initiates UPR. Attenuation of ER stress in senescent OSE by tauroursodeoxycholic acid (TUDCA) reconditions ER architecture and leads to delayed onset of senescence. In summary, we show for the first time a mutual molecular link between ER stress response and replicative senescence leading to phenotypic changes of non-malignant ovarian surface epithelium.

• MeSH
• down regulace účinky léků   MeSH
• epitel účinky léků   patologie   ultrastruktura   MeSH
• kyselina taurochenodeoxycholová farmakologie   MeSH
• messenger RNA genetika   metabolismus   MeSH
• myši MeSH
• ovarium patologie   MeSH
• stárnutí buněk účinky léků   MeSH
• stres endoplazmatického retikula účinky léků   MeSH
• tunikamycin farmakologie   MeSH
• upregulace účinky léků   MeSH
• zkracování telomer účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The accumulation of senescent cells drives inflammaging and increases morbidity of chronic inflammatory lung diseases. Immune responses are built upon dynamic changes in cell metabolism that supply energy and substrates for cell proliferation, differentiation, and activation. Metabolic changes imposed by environmental stress and inflammation on immune cells and tissue microenvironment are thus chiefly involved in the pathophysiology of allergic and other immune-driven diseases. Altered cell metabolism is also a hallmark of cell senescence, a condition characterized by loss of proliferative activity in cells that remain metabolically active. Accelerated senescence can be triggered by acute or chronic stress and inflammatory responses. In contrast, replicative senescence occurs as part of the physiological aging process and has protective roles in cancer surveillance and wound healing. Importantly, cell senescence can also change or hamper response to diverse therapeutic treatments. Understanding the metabolic pathways of senescence in immune and structural cells is therefore critical to detect, prevent, or revert detrimental aspects of senescence-related immunopathology, by developing specific diagnostics and targeted therapies. In this paper, we review the main changes and metabolic alterations occurring in senescent immune cells (macrophages, B cells, T cells). Subsequently, we present the metabolic footprints described in translational studies in patients with chronic asthma and chronic obstructive pulmonary disease (COPD), and review the ongoing preclinical studies and clinical trials of therapeutic approaches aiming at targeting metabolic pathways to antagonize pathological senescence. Because this is a recently emerging field in allergy and clinical immunology, a better understanding of the metabolic profile of the complex landscape of cell senescence is needed. The progress achieved so far is already providing opportunities for new therapies, as well as for strategies aimed at disease prevention and supporting healthy aging.

• MeSH
• chronická nemoc MeSH
• chronická obstrukční plicní nemoc metabolismus   farmakoterapie   imunologie   MeSH
• lidé MeSH
• metabolické sítě a dráhy * MeSH
• plicní nemoci etiologie   farmakoterapie   metabolismus   imunologie   MeSH
• stárnutí buněk * účinky léků   MeSH
• stárnutí imunologie   metabolismus   MeSH
• zánět metabolismus   imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

• MeSH
• apoptóza účinky záření   MeSH
• buněčná smrt MeSH
• stárnutí buněk účinky léků   MeSH

• MeSH
• inzulinová rezistence imunologie   MeSH
• lidé MeSH
• PPAR gama imunologie   metabolismus   MeSH
• stárnutí buněk genetika   imunologie   účinky léků   MeSH
• svalové atrofie imunologie   komplikace   MeSH
• svalové proteiny imunologie   škodlivé účinky   MeSH
• Check Tag
• lidé MeSH

OBJECTIVES: Chemotherapeutic drugs induce senescence in cancer cells but, unlike replicative senescence or oncogene-induced senescence, do so rather inefficiently and depending on DNA damage. A thorough understanding of the biology of chemotherapy-induced senescent cells requires their isolation from a mixed population of adjacent senescent and non-senescent cancer cells. MATERIALS AND METHODS: We have developed and optimized a rapid iodixanol (OptiPrep)-based gradient centrifugation system to identify, isolate and characterize doxorubicin (DXR)-induced senescent hepatocellular carcinoma (HCC) cells (HepG2 and Huh-7) in vitro. RESULTS: After cellular exposure to DXR, we used iodixanol gradient-based centrifugation to isolate and re-plate cells on collagen-coated flasks, despite their low or null proliferative capacity. The isolated cell populations were enriched for DXR-induced senescent HCC cells, as confirmed by proliferation arrest assay, and β-galactosidase and DNA damage-dependent γH2A.X staining. CONCLUSIONS: Analysing pure cultures of chemotherapy-induced senescent versus non-responsive cancer cells will increase our knowledge on chemotherapeutic mechanisms of action, and help refine current therapeutic strategies.

• MeSH
• doxorubicin farmakologie   MeSH
• hepatocelulární karcinom patologie   MeSH
• kyseliny trijodbenzoové farmakologie   MeSH
• lidé MeSH
• nádory jater patologie   MeSH
• poškození DNA účinky léků   MeSH
• separace buněk * metody   MeSH
• stárnutí buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Cellular senescence provides a biological barrier against tumor progression, often associated with oncogene-induced replication and/or oxidative stress, cytokine production and DNA damage response (DDR), leading to persistent cell-cycle arrest. While cytokines such as tumor necrosis factor-alpha (TNFα) and interferon gamma (IFNγ) are important components of senescence-associated secretome and induce senescence in, for example, mouse pancreatic β-cancer cell model, their downstream signaling pathway(s) and links with oxidative stress and DDR are mechanistically unclear. Using human and mouse normal and cancer cell models, we now show that TNFα and IFNγ induce NADPH oxidases Nox4 and Nox1, reactive oxygen species (ROS), DDR signaling and premature senescence. Unlike mouse tumor cells that required concomitant presence of IFNγ and TNFα, short exposure to IFNγ alone was sufficient to induce Nox4, Nox1 and DDR in human cells. siRNA-mediated knockdown of Nox4 but not Nox1 decreased IFNγ-induced DDR. The expression of Nox4/Nox1 required Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling and the effect was mediated by downstream activation of transforming growth factor-beta (TGFβ) secretion and consequent autocrine/paracrine activation of the TGFβ/Smad pathway. Furthermore, the expression of adenine nucleotide translocase 2 (ANT2) was suppressed by IFNγ contributing to elevation of ROS and DNA damage. In contrast to mouse B16 cells, inability of TC-1 cells to respond to IFNγ/TNFα by DDR and senescence correlated with the lack of TGFβ and Nox4 response, supporting the role of ROS induced by NADPH oxidases in cytokine-induced senescence. Overall, our data reveal differences between cytokine effects in mouse and human cells, and mechanistically implicate the TGFβ/SMAD pathway, via induction of NADPH oxidases and suppression of ANT2, as key mediators of IFNγ/TNFα-evoked genotoxicity and cellular senescence.

• MeSH
• enzymová indukce účinky léků   MeSH
• interferon gama farmakologie   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• NADPH-oxidasy biosyntéza   genetika   MeSH
• oxidační stres účinky léků   MeSH
• poškození DNA * MeSH
• proteiny Smad metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• signální transdukce účinky léků   MeSH
• stárnutí buněk účinky léků   MeSH
• TNF-alfa farmakologie   MeSH
• transformující růstový faktor beta metabolismus   MeSH
• transkripční faktory STAT metabolismus   MeSH
• translokátor adeninových nukleotidů 2 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Spectral karyotyping (SKY) represents an important tool for the investigation of the complex chromosomal rearrangements (CCRs) in many human malignancies which may be difficult to characterize by conventional banding techniques. The main goal of our work was to optimize the most important steps in the preparation of molecular cytogenetic slides for a SKY protocol. This approach consisted of optimization of both the aging procedure and protease pretreatment of the slides, with special regard given to the preservation of chromosome structure and shape, as well as to the intensity of hybridization signals. The best results were obtained with a chemical aging procedure using SSC or ethanol in combination with trypsin pretreatment applied at a higher concentration for a shorter period of pretreatment. A resulting protocol for SKY also applicable to human solid tumour cells was subsequently proposed. The practical potential of the SKY technique was demonstrated on examples of two types of human embryonal tumours--neuroblastoma and Wilms' tumour, in which some kinds of chromosomal aberrations were not detectable by means of classic cytogenetic methods. Copyright 2007 S. Karger AG, Basel.

• MeSH
• dítě MeSH
• financování organizované MeSH
• hybridizace nukleových kyselin MeSH
• indoly MeSH
• krevní buňky cytologie   účinky léků   MeSH
• lidé MeSH
• metafáze účinky léků   MeSH
• neuroblastom genetika   patologie   MeSH
• odběr biologického vzorku metody   MeSH
• proteasy farmakologie   MeSH
• spektrální karyotypizace metody   MeSH
• stárnutí buněk účinky léků   MeSH
• Wilmsův nádor genetika   patologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH

Cellular senescence, an irreversible proliferation arrest evoked by stresses such as oncogene activation, telomere dysfunction, or diverse genotoxic insults, has been implicated in tumor suppression and aging. Primary human fibroblasts undergoing oncogene-induced or replicative senescence are known to form senescence-associated heterochromatin foci (SAHF), nuclear DNA domains stained densely by DAPI and enriched for histone modifications including lysine9-trimethylated histone H3. While cellular senescence occurs also in premalignant human lesions, it is unclear how universal is SAHF formation among various cell types, under diverse stresses, and whether SAHF occur in vivo. Here, we report that human primary fibroblasts (BJ and MRC-5) and primary keratinocytes undergoing replicative senescence, or premature senescence induced by oncogenic H-Ras, diverse chemotherapeutics and bacterial cytolethal distending toxin, show differential capacity to form SAHF. Whereas all tested cell types formed SAHF in response to activated H-Ras, only MRC-5, but not BJ fibroblasts or keratinocytes, formed SAHF under senescence induced by etoposide, doxorubicin, hydroxyurea, bacterial intoxication or telomere attrition. In addition, DAPI-defined SAHF were detected on paraffin sections of Ras-transformed cultured fibroblasts, but not human lesions at various stages of tumorigenesis. Overall, our results indicate that unlike the widely present DNA damage response marker γH2AX, SAHF is not a common feature of cellular senescence. Whereas SAHF formation is shared by diverse cultured cell types under oncogenic stress, SAHF are cell-type-restricted under genotoxin-induced and replicative senescence. Furthermore, while the DNA/DAPI-defined SAHF formation in cultured cells parallels enhanced expression of p16(ink4a) , such 'prototypic' SAHF are not observed in tissues, including premalignant lesions, irrespective of enhanced p16(ink4a) and other features of cellular senescence.

• MeSH
• bakteriální toxiny farmakologie   MeSH
• buněčné linie MeSH
• geny ras MeSH
• heterochromatin chemie   MeSH
• inhibitor p16 cyklin-dependentní kinasy genetika   metabolismus   fyziologie   MeSH
• lidé MeSH
• poškození DNA MeSH
• proliferace buněk MeSH
• stárnutí buněk účinky léků   genetika   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH